Oxygen sensor before catalytic converter, bank 2 (left side), removing and installing

WARNING: This page is about a different car, the 2009 Audi A4, 2008 Audi A4, 2007 Audi A4, 2006 Audi A4, and 2005 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Special tools, testers and auxiliary items required

Fig 1: Identifying Ring Spanner 7-Piece Set 3337

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Ring spanner 7-piece set for oxygen sensor 3337

Removing

NOTE:

All cable ties opened or cut during engine removal must be reinstalled at the same locations during installation.

Fig 2: Removing Rear Engine Cover

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Remove rear engine cover - arrows -.

Fig 3: Removing Coolant Hoses At Coolant Expansion Tank

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Remove coolant expansion tank - arrow -.
Disconnect electrical connection from Engine Coolant Level (ECL) Warning Switch F66 at bottom of coolant reservoir and set aside coolant reservoir with coolant hoses - 1 - and - 2 - connected.

Fig 4: Disconnecting Electrical Harness Connector For Heated Oxygen Sensor (HO2S) 2 G108

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Disconnect electrical harness connector - 2 - for Heated Oxygen Sensor (HO2S) 2 G108 and free up wire.

NOTE:

Ignore - 1 -.

Fig 5: Removing Oxygen Sensor Using Ring Spanner Set 3337

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Remove oxygen sensor - 1 - using ring spanner set 3337.

NOTE:

To improve clarity, the engine is removed.

Installing

Installation is in reverse order of removal, note the following:

NOTE:

New oxygen sensors are coated with assembly paste; the paste must not get into slots of oxygen sensor body.
When reinstalling the previously used oxygen sensor, coat thread with hot bolt paste . Paste must not get on to slits of sensor body.
During installation, all cable ties must be re-installed at the same location.
Wires of oxygen sensors must always be secured in the same position when installing so that contact with the exhaust pipe is avoided.

Torque specifications

Component	Nm
Oxygen sensor in front exhaust pipe	55